Light source



FIG. 1 is a side view of the light source showing the design;

FIG. 2 is a top plan view of the light source showing the design;

FIG. 3 is a bottom plan view of the light source showing the design; and,

FIG. 4 is a side perspective view of the light source showing the design.

The broken lines in the drawing are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a light source, as shown and described. 